- Run Windows Search and look for cygwin1.dll file.- Find recent file and copy it to %WIN%\System32\ folder. %WIN% - folder where Windows installed.- Delete all other files. You should have only one file inside %WIN%\System32\ folder.- Reboot PC. After this both compilers should work well.

[2] Why is the download slow ?

If you are using a USB to COM converter such as CBL-USB-COM-1 from BiPOM, please change the latency timer settings of the USB to COM converter. See the document: CBL-USB-COM-1 Speed Improvements